Interesting hand, how' would you play it?

[FletchJr.]

As u can see it's getting very late in the tourney, my opponents are still gambling a lot but they just won't die!
I've been avoiding some hands for a while and decide to play this one.

Party Poker No-Limit Hold'em Tourney, Big Blind is t200 (4 handed)

Button (t3630)
SB (t250)
Hero (t1370)
UTG (t2750)

Preflop: Hero is BB with T[img]/images/graemlins/heart.gif[/img], A[img]/images/graemlins/heart.gif[/img].
UTG raises to t400, Button calls t400, SB calls t150 (All-In), Hero calls t200.

Flop: (t1450) 2[img]/images/graemlins/diamond.gif[/img], Q[img]/images/graemlins/heart.gif[/img], 5[img]/images/graemlins/heart.gif[/img] <font color="blue">(4 players, 1 all-in) </font>
Hero checks, UTG checks, Button checks.

Turn: (t1450) J[img]/images/graemlins/diamond.gif[/img] <font color="blue">(4 players, 1 all-in) </font>
Hero checks, UTG bets t200, Button folds, Hero calls t200.

River: (t1850) 8[img]/images/graemlins/spade.gif[/img] <font color="blue">(3 players, 1 all-in) </font>
Hero checks, UTG checks.

Final Pot: t1850

Results in white below: <font color="white">
SB shows As 8d (one pair, eights).
Hero shows Th Ah (high card, ace).
UTG shows 9h Kh (high card, king).
Outcome: SB wins t1000. Hero wins t850. </font>

Who here doesn't even play the hand?
who goes all in on a semibluff on the flop or teh turn?
and why? thanks ahead.